1. Field of the Invention
The present invention is related to toning for connectivity and speed handshaking in Beta and/or Bilingual ports of IEEE1394 devices.
2. Background Art
Several specifications or standards have been implemented that specify requirements for FireWire (Apple), i.link (Sony), and IEEE1394. These standards were implemented in 1995 (IEEE1394-1995), 2000 (IEEE-1394a-2000), and 2002 (IEEE1394b-2002). All the standards for IEEE1394 describe a general high speed serial interface or a serial bus for cable or backplane media to transmit and receive data traveling at about 25 Mbit/sec (Mbps) to about 2 Gbit/sec (2 Gbps), with higher speeds contemplated in the future. IEEE1394b is intended to provide more media (e.g., optical media, UTP-5 cable, etc.) and higher data rates. The 1995 and 2000 standards are usually collectively referred to as Legacy or DS (data-strobe) and the 2002 standard is referred to as Beta.
Requirements for a Bilingual port have also been added to the IEEE1394 specifications. A Bilingual port is a single port that includes a system allowing for transceiving of both Legacy and Beta signals. For example Bilingual ports, reference can be made to U.S. patent application Ser. No. 10/660,670, filed Sep. 12, 2003, entitled “Serial Data Interface System And Method Having Bilingual Functionality,” to van Engelen et al., which is incorporated by reference herein in its entirety.
Conventional functionality and devices described in detail in the standards noted above are not repeated within this document. The standards listed above are all incorporated by reference herein in their entireties.
Beta signaling is usually done using serializer/deserializer (SerDes) technology for its dual simplex signaling scheme. For example, when two twisted-pairs (TPs) are used for the short-haul copper media, a first TP is used only to transmit from a serializer and a second TP is used only to receive at a deserializer. All idle, arbitration, and packet speed information is transmitted as symbols in the data, which can allow for continuous clock recovery. A special toning scheme is used to check for connection and signal speed. An on/off keyed tone is send as a differential output signal with a certain output amplitude, frequency, and repetition.
As discussed above, toning is used for speed and connectivity determination in Beta signal ports. Therefore, what is needed is a simple and inexpensive system and method for toning.